Atomic Defects in Metals · Zr

In this chapter, resistivity annealing of zirconium (Zr) has been investigated after e^--irradiation, fast n-irradiation and plastic deformation. Due to the temperature limitations by the phase transformation at 1138 K and the impurity problems no quantitative results on vacancies have been obtained after quenching. The large annealing stage I is observed after all irradiations. The attribution to SIA migration is supported by MechR and by the observation of SIA clustering by DXS. The large low temperature annealing stage that is observed after plastic deformation seems to be related to oxygen impurities. The temperature of annealing stage II is dose dependent and vacancy clustering has been observed by PAS. The chapter also discusses the properties of Frenkel defects (FD), self-interstitial atoms (SIA), and vacancies (V) and defect-solute atom (SA) interaction, SIA-SA and V-SA interaction. Interstitial trapping has been observed for several solute atoms: Au, Nb, Ti. From PAS investigations of Zr-Sn a small binding energy was deduced for the SnV complex and a much larger one for Sn_xV. There is nearly no influence of oxygen on the annealing after e^--irradiation in contrast to the large effects of oxygen on the annealing after plastic deformation. For zircaloy-2 and zircaloy-4 a suppression of the major annealing peaks is observed after fast n-irradiation, however, no additional annealing peaks are observed.